Popular Books on Natural Science

tion or a myth. At present, however, when daily opportunity is afforded to admire, for example, the velocity of the electric current in the electro-

ings every one may observe for himself; then, even the greatest sceptic among you will clearly see, that the change-or "electric force

n, is electrified at one end, the electric current will manifest itself at the other end in the same moment. From this it follows, that the electric force travels with such speed as to

e may be, the result has always been, that the time which electricity needs to run that distance, is

transmission of effect from one end of the wire to the other end does not require any time at all, b

or it to be transmitted from one place to another; that this certain amount of time is imperceptible to us for this reason, viz., that all distances whi

for common observation, because the electric force would run even through th

hundred and fifty thousand miles in a second. But how could this have

a little thinking, we will try to represent the way in which this measurement was ta